I thought it was worth mentioning that in one of the upcoming releases, JoinFS will include an additional user permission.

From now on, multiple objects (other than the other users' main aircraft) will not be processed or injected by default. The only aircraft in any session that will be seen will be the other user's primary controlled aircraft. If you wish to see other aircraft broadcast by a specific user you will need to open the user list and permission options and enable 'Allow multiple objects'. You'll then see all of the aircraft and objects broadcast by that user.

By design this also applies to hubs, so in case where a hub is broadcasting objects, you need to enable permission on that hub's own user.

Please note that this now means you can safely join the global session without being flooded with numerous objects and AI aircraft.